The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The functional vessels of human and animal bodies, such as blood vessels and ducts, occasionally weaken or even rupture. For example, the aortic wall can weaken, resulting in an aneurysm. One surgical intervention for weakened, aneurismal, or ruptured vessels involves the use of stents or stent grafts to cover the weakened spot in the blood vessel. Stents can be either balloon-expanding (BX) or self-expanding (SX), depending on how the stents are deployed in the body lumen.
The stent, when placed in a body lumen, is subjected to force from blood or other fluid flow. The stent is required to have predetermined radial stiffness, radial strength, and reduced foreshortening to keep the stent in a desired location without being dislodged. Foreshortening refers to the percentage by which the length of a stent decreases from its unexpanded state to its expanded state. It is common for typical stents to experience foreshortening due to radial expansion of the stent. A significant amount of foreshortening of the stent can result in a reduced length of the stent and consequently reduced coverage of the stent against the wall of the lumen.